Lecture 15

Question 1

What are bile acids synthesised from?

Answer 1

cholesterol

Question 2

What are the two primary bile acids?

Answer 2

Cholic acid and chenodeoxycholic acid

Question 3

How many OH groups do the primary bile acids have?

Answer 3

Cholic acid has 3, chenodeoxycholic acid has 2

Question 4

How are secondary bile acids formed?

Answer 4

By 7-alpha dehydroxylation.

Question 5

Which secondary bile acid is insoluble and lost in faeces?

Answer 5

Lithocholic acid

Question 6

What two amino acids are conjugated to bile salts?

Answer 6

Glycine and taurine in a 3:1 ratio

Question 7

What hormone tells the gall bladder to release bile?

Answer 7

cholecystokinin

Question 8

At what point are most bile salts reabsorbed?

Answer 8

In the terminal ileum

Question 9

How many recirculation’s a day occur for a bile salt?

Answer 9

6-10

Question 10

What are the ileum apical transporters?

Answer 10

ASBT (conjugated bile salts)

Question 11

What is the ileum basolateral transporter?

Answer 11

OST-alpha/OST-beta

Question 12

How do bile salts travel in blood?

Answer 12

Bound to albumin

Question 13

What are the sinusoidal transporters?

Answer 13

NTCP and OATP1B1/OATP1B3

Question 14

What are the cannalicular transporters?

Answer 14

BSEP and MRP2

Question 15

What is cobalamin?

Answer 15

A coenzyme in the synthesis of RNA and DNA

Question 16

Vitamin B12 deficiency causes what?

Answer 16

Pernicious anaemia

Question 17

What does cobalamin bind to in the stomach?

Answer 17

Haptocorrin

Question 18

What does cobalamin bind to in the duodenum?

Answer 18

Intrinsic factor

Question 19

How does the cobalamin-IF complex enter the cell?

Answer 19

Receptor mediated endocytosis.

Question 20

What does cobalamin bind to inside the cell?

Answer 20

transcobalamin II